Middle plate in a cylinder lock

ABSTRACT

A lock cylinder, turnable by a key, carries tumblers which support plates interleaved between the tumblers. The interleaved plates comprise outwardly pressed portions keeping the tumblers in place.

United States Patent [I5] 3,681,956 Niilola [451 Aug. 8, 1972 [54] MIDDLE PLATE IN A CYLINDER [56] References Cited LOCK FOREIGN PATENTS OR APPLICATIONS 72 I t l 1 fig g g i fi xfig 25,706 12/1952 Finland ..70/366 22,581 6/1948 Finland ..70/366 [22] Filed: Nov. 12, 1970 266,856 5/1950 Switzerland ..70/366 [21] Appl' 88702 Primary Examiner-Robert L. Wolfe Attorney-Kurt Kelman [30] Foreign Application Priority Data [57] ABSTRACT N 17, I969 7 9 9 0v Sweden 2 [196 A lock cylinder, tumable by a key, carries tumblers which support plates interleaved between the tumil blew The interleaved plates comprise outwardly 58 Field o'i'rliillll'. 26/528335 377 372 pressed Wmnskeepmg thewmblersm place 3 Claims, 5 Drawing Figures PATENTEDAUG 8 1912 INVENTOR:

HRMAS K- N/ILOLF} BYI MIDDLE PLATE IN A CYLINDER LOCK Cylinder lock means in this description a lock, where the case of the lock body comprises a cylinder and in this detent plates, turnable by a key, and, supported by these, middle plates. By turning the key, the detent plates turn to an opening position and to a locking position. The middle plates do not take part in the turning movements of the detent plates, on the contrary, they remain in their position with reference to the cylinder. The purpose of the middle plates is that the turning of the detent plates is actuated only by the key and not by the turning of the adjacent detent plate. Another purpose of the middle plates is to keep the plate pile in axial direction under appropriate pressure so that the detent plates stay in their place when the keyhas been drawn out from the lock. Therefore the middle plates have been made springlike, by giving them a convex disk-like shape and by making them for example of spring bronze.

A drawback in the known locks of above-described type is that the middle plates get looser with time, whereat the detent plates will turn when the key has been taken out from the lock. The more the lock is susceptible to moving and shaking, the greater the risk, caused by such a movement of the detent plates. In case the detent plates turn when the key has been taken out from the lock, it is difiicult and sometimes even impossible to insert the key in the lock. The invention aims at obtaining in this respect a better middle plate for cylinder locks, which due to the invention become more secure at use, without a considerable increase of the coast of manufacturing. A lock according to the invention is particularly fit for use when the lock becomes susceptible to movement and shaking. This is true particularly as to the locks at vehicles and cars. The lock according to the invention is thus considerably better as a car lock than the known cylinder locks.

The invention is described more precisely in the following with reference to the attached drawing, where FIG. 1 shows the lock with inserted key in longitudinal section.

FIG. 2 shows a crosscut along the line 2-2 in FIG. 1.

FIG. 3 shows a crosscut along the line 3--3 in FIG. 1.

FIG. 4 shows a middle plate according to the invention, seen in the axial direction of the lock.

FIG. 5 shows a projection of the middle plate along the line 5-5 in FIG. 4.

The embodiment illustrated by the drawing refers to a so-called cylinder lock, where the cylinder case of the lock body 1 contains a cylinder 2 and in this detent plates 4, turnable by the key 3, and, supported by these detent plates, middle plates 5. Such a cylinder lock is previously known. The lock is opened and locked by turning the key 3 in one or another direction, whereat the key turns the detent plates 4. The middle plates 5 do not take part in this turning, due to the fact that the part 7 of the peripherical sector is situated in a section of the cylinder 2.

It is previously known to make the middle plate 5 springlike, by giving it a shape of a cup and by making the middle plate of elastic material, as spring bronze. These measures are not, however, sufficient to secure an effective function of the middle'plates under exacting circumstances, where the lock is susceptible to motion an prove comprises according to the invention, in the peripherical sector 7 of the middle plate, a portion 6, pressed outward, which appears especially in FIG. 5, where the middle plate is otherwise planelike. Differing from this, the middle plate can furthermore be cup-shaped or entirely slightly twisted.

According to another characteristic a middle plate according to the invention involves the fact that the opening 8 in the middle plate is larger than in the known middle plates. In addition to this, the opening 8 stretches outward at the peripherical sector 7, as shown by the reference number 9 in Fig. 4. v

In a normal case one middle plate 5 is always situated between two detent plates but, furthermore, the middle plate can be used between the extreme detent plates 4 and the cylinder or the lock case I. In these places or at the ends of the entire plate packet a fitting can also be used where two middle plates are situated adjacent to each other, with projections 6 against each other.

The invention is not confined to the embodiment described above and illustrated in the drawing; other embodiments are also possible within the scope of the claims attached hereto. Particularly, a middle plate according to the invention can be applied at locks having details which are different from those described above.

I-claim:

1. A lock comprising a lock body, a lock cylinder in the lock body, a plurality of detent plates in the lock cylinder and movable by a key inserted into the lock cylinder, and plates supported by, and intermediate, adjacent ones of the detent plates, each of the intermediate plates comprising a portion located in a sector cam on the outer periphery thereof and being pressed outward from the plane thereof to keep the detent plates in their place.

2. The lock of claim 1, wherein each intermediate plate defines a central opening having an enlarged part adjacent the peripheral cam.

3. The lock of claim 1, wherein two of the intermediate plates are mounted between the adjacent detent plates, the sector cam portions thereof being directed towards each other. 

1. A lock comprising a lock body, a lock cylinder in the lock body, a plurality of detent plates in the lock cylinder and movable by a key inserted into the lock cylinder, and plates supported by, and intermediate, adjacent ones of the detent plates, each of the intermediate plates comprising a portion located in a sector cam on the outer periphery thereof and being pressed outward from the plane thereof to keep the detent plates in their place.
 2. The lock of claim 1, wherein each intermediate plate defines a central opening having an enlarged part adjacent the peripheral cam.
 3. The lock of claim 1, wherein two of the intermediate plates are mounted between the adjacent detent plates, the sector cam portions thereof being directed towards each other. 